According to DE 19015324, fittings are referred to as automatic fittings if the water supply of a washstand fitting is controlled via an external solenoid valve and the existing fitting is only still used for preselecting the mixing ratio and as a sensor.
DE 19651132 also discloses an automatic fitting, which is equipped with a sensor unit and a control unit as a proximity fitting. A valve unit and/or a valve battery is connected to the control unit, the control unit activating the valve unit to release water after registering a signal through the sensor unit. In this special case, the release of cold water or hot water is caused upon registering a signal detected by the infrared sensors from a specific side.
A further proximity fitting is known from WO 93/10311. A proximity sensor detects the hand of the user and releases the water supply. After the passage of a time interval, a soap portion is dispensed and the washing procedure is registered.
Another automatic fitting is known from DE 3516440. This arrangement having a panel of monitoring sensors allows the contactless regulation of the supply and/or the mixing ratio of hot and cold water. A fixed temperature and/or discharge quantity value is assigned to every monitoring sensor, which work hierarchically with one another.
A further automatic fitting is known from WO 02/29168. This is a device for controlling a medium supply having a sensor device for contactless determination of the presence and position of a hand of the user, the sensor device establishing an electrical charge transfer.
In addition, an electronic control for a water tap, a nozzle, and the like is known from U.S. Pat. No. 5,095,945 to Jensen. Water inlets are all equipped with solenoid valves, which are controlled via a logical controller. This controller is connected to a detector, which detects the proximity of a user hand and provides an output signal which causes the controller to run through a sequence of selected temperatures and time limits until the user—upon reaching a desired temperature and duration—moves his hand out of the proximity of the sensor. The controller then outputs signals to the solenoid valves so that these allow water to flow through the inlets into the water distributor and from there to the tap, the nozzle, etc. in accordance with the selected temperature and duration. The user is always offered the identical series of selection possibilities. This series is displayed by LED and must be run through every time until the system displays the desired parameter combination. The user must pull back his hand in this moment and the system releases water corresponding to the selected parameters. Therefore, the water removal is programmed without water flowing. The detection system disclosed comprises an infrared transmitter (LED) and an infrared receiver (photodiode) and is based on the detection of the infrared light reflected in the sensor.
FR 2706504 discloses a further electronic fitting controller having a presence detector, at least one electronic valve, and an electronic circuit which allows the presence detector to generate control signals, which processes the response signal in accordance with the detection of presence or absence and which triggers the opening or closing of the electronic valve 7. A pulsed, active infrared sensor and a comparison of the detected infrared light to a threshold value is disclosed. Setting or changing a temperature and/or a flow value is not disclosed.
Most of these known automatic fittings and/or their controllers are constructed very simply and allow only the supply of a previously determined water temperature and/or of hot or cold water (e.g., FR 2706504). Few of the known automatic fittings also allow the adjustment of the water temperature (e.g., U.S. Pat. No. 5,095,945), and such fittings and/or their controllers usually have quite complex constructions and are therefore costly. The operation of the controllers, which are often complex, is rather difficult to understand or cumbersome for a first-time user. Additional selection handles or even touch screens for setting water temperature and/or water flow may simplify the operation, but make the fitting more expensive.
U.S. Pat. No. RE 37,888E to Cretu-Petra discloses a water faucet with touchless control of water temperature and water flow adjustment. The assembly comprises a water mixing valve and three touchless proximity sensors. Each one of these proximity sensors is located at the faucet behind an individual lens. A first one of these sensors is accomplished for switching on and off the water flow, a second one of these sensors is accomplished to control the water flow, and a third one is utilized for controlling the water temperature. All sensors detect hand movements in the proximity of the sensors by the reflexion of infrared light which they emit. Using these sensors by adjusting a certain distance between the hand and the sensor, a certain temperature or flow of the water can be adjusted. This reference discloses that pre-programmed settings of flow and temperature can be accessed with defined commands. At col. 10, lines 2-6, it is taught that adjustment of these settings also can be made while water is flowing into the faucet. At col. 8, lines 42-45, it is taught that, after activation of the on/off sensor the water supply is stopped after a certain pre-selected time. Cretu-Petra fails to provide a teaching, however, regarding an individual time slot that is assigned to each action signal and that is utilized to control the flow and/or temperature of water.
The control of water flow and temperature according to Cretu-Petra is based on a continuous movement of the user's hand with respect to the infrared sensor in each case. The signal initiated by such movements is also continuous as long as the hand rests inside the field of detection of the respective sensor. Thus, there is a need for a device that provides punctual and discontinuous action signals, to the end of which a time slot can be easily assigned. The continuous control taught by Cretu-Petra does not allow for the definition of such a time slot, the time slot being individually assigned to each action signal that is triggered by a trigger means.
U.S. Pat. No. 5,031,258 to Shaw discloses a wash station and with an electrically activatable valve on the tap. On or at the faucet of this wash station, there is located an infrared sensor which detects the presence of a user's hands. In order to avoid unintentional activation of the wash station, the sensor must be activated over a certain time span. Then, the wash table can be used in a “normal” or “automatic” mode. In order to utilize the “automatic” mode, the user needs to move his hands in the detection field of the sensor and within a defined time interval (see col. 8, lines 25-32). In case of lack of such detectable movement, the station changes to the “normal” mode. Shaw is silent about an individual time slot that is assigned to each action signal and that is utilized to control the flow and/or temperature of water.